.Dd 2015-10-08 .Dt COMM 1 .Os sbase .Sh NAME .Nm comm .Nd select or reject lines common to two files .Sh SYNOPSIS .Nm .Op Fl 123 .Ar file1 .Ar file2 .Sh DESCRIPTION .Nm reads .Ar file1 and .Ar file2, which should both be sorted lexically, and writes three text columns to stdout: .Bl -tag -width Ds .It 1 Lines only in .Ar file1 . .It 2 Lines only in .Ar file2 . .It 3 Common lines. .El .Sh OPTIONS .Bl -tag -width Ds .It Fl 1 | Fl 2 | Fl 3 Suppress column 1 | 2 | 3 .El .Sh SEE ALSO .Xr cmp 1 , .Xr sort 1 , .Xr uniq 1 .Sh STANDARDS The .Nm utility is compliant with the .St -p1003.1-2013 specification.